Practice for the game of tennis is necessary to develop the skills required. However the game requires at least two players and a practicing player may not want or be able to join another player for practice. Practicing alone on a regulation court can be accomplished, but one must be able to store a large number of tennis balls and be able to retrieve these balls or the practice primarily turns into an exercise in obtaining and retrieving tennis balls.
Retrieving tennis balls is an especially tedious, time consuming and unproductive task for a student or teacher or practicing player. One alternative is not to practice in a regulation tennis court, but to practice against a wall. This is not satisfactory to many players as it changes the character of the play. Mechanical serving devices are also available, but again reloading the device and collection of balls are a time consuming process. Other alternatives on a tennis court are to employ various practice aids, including types of ball sweeping/collection and ball storage and dispensing devices.
The primary objectives for a practice aid are (1) the practice aid must have a high capacity for the storage of tennis balls, (2) be conveniently within reach for dispensing balls and (3) be able to quickly collect balls laying at random on the court. Practice aid should be small so that it will not interfere with the practice and not overly obstruct the court. It should also be light weight, rugged in construction, pleasing in appearance and low in cost. When the practice aid is deployed in each of the three modes (collection, storage and dispensing), a minimum of effort to convert from one mode to another mode is also desirable.
Most of the current practice aids may do one of these objectives well, but others poorly or not at all. Ball hoppers conveniently provide access to dispense balls during practice, but many do not allow storage (covered) or transport. Others provide storage and access, but do not retrieve balls.
Ball storage devices also tends to be separate, typically in the can in which purchased. Transport to and from the storage location requires lifting. Larger storage devices accommodate many balls but are difficult to lift and transport.
Ball retrievers tend to be complex and cumbersome, limiting transport, access and use. Examples of ball collectors which do not function in the other modes and do not satisfy the other practice objectives include U.S. Pat. Nos. 2,484,437; 4,318,654; and 3,717,371. All of these devices only collect balls and all require separate hinged/rotating and/or fixed fingers/projections to lift and/or remove balls for placement into a receptacle. Many of these devices also tend to get caught by nets and fencing. Since these locations are likely places for balls to come to rest, this can be a major problem.
Prior art which attempts to accomplish all three of the primary objectives tend to be even more complex and cumbersome to lift, transport and use. U.S. Pat. No. 4,252,490 uses a spring loaded trapping mechanism, a non rotating ball engaging surface mounted to a jointed frame which allows multiple positions, wheels and a handle. The handle also serves as one of the supports when the device is used to dispense balls, but fold out legs are also required. The cage is also separate from the structure which supports these folding, multiposition elements. In addition, the spring mechanism must be periodically actuated, i.e: the process is a batch type for each ball or group of balls, rather than a continuous process.
In another approach to achieving a multimode practice aid, U.S. Pat. No. 4,077,533 uses a rotating drum, belt driven by traction wheels and axle, removable extension members to support the device in the dispensing position, a removable ball receptacle, a frame, a means to adjust the frame, an arcuate ball guide, and handle. Handle can be folded out of the way of the player during the dispensing mode and a ball guide with wheels can be used for partial support in the dispensing mode.
These prior multi-mode approaches have many limitations. These are primarily related to the multiplicity of elements required to accomplish the three operating modes, creating added cost, weight and space. This multiplicity of elements, weight and space particularly detract from the storage and dispensing modes. In addition, they also tend to get caught by nets and fencing located within the court in the collecting mode of operation.
None of the prior art cited incorporates positive collection (balls retained in a container with covered openings or openings smaller than the ball diameter) to allow immediate transport and storage without the use of additional movable elements in addition to traction wheels and an axle. None allows conversion to a dispensing mode without additional structure. All also tend to get caught when in contact with nets or fences when in the collecting mode.